Smoke and Carbon Monoxide Alarms for the Home and Rental Units

Updated Smoke Alarm Requirement 

It is highly recommended to have smoke alarms installed in all homes, including single-family residences.  In certain situations, smoke alarms are required by law. 

For all dwelling units intended for human occupancy for which a building permit is issued on or after January 1, 2014, for alterations, repairs, or additions exceeding one thousand dollars ($1,000), the permit issuer shall not sign off on the completion of work until the permittee demonstrates that all smoke alarms required for the dwelling unit are devices approved and listed by the CA Office of the State Fire Marshal (OSFM).  For current smoke alarm listings, please consult the OSFM Building Materials Listings - Search Listing Services website. 

As of July 1, 2014, new smoke alarms that are solely battery powered must have a nonreplaceable, nonremovable battery that is capable of powering the smoke alarm for at least 10 years.

Beginning January 1, 2015, all smoke alarms shall display: the date of manufacture on the device; provide a place on the device where the date of installation can be written, and; incorporate a hush feature.

By January 1, 2016, owners of a dwelling unit intended for human occupancy in which one or more units is rented or leased shall install additional smoke alarms, as needed, to ensure that smoke alarms are located in compliance with current building standards.  Existing alarms installed need not be replaced unless the alarm is inoperable.

Existing installed operable/in working condition smoke alarms are not required to be replaced.  However, smoke alarms should be replaced every 10 years, or per the manufacturer's instructions.

For more information on smoke alarms and carbon monoxide alarms, including where they are required to be placed, please see:


Update Carbon Monoxide Alarm Requirements

As of July 1, 2011, the Carbon Monoxide Poisoning Prevention Act (SB 183) requires all single-family homes with an attached garage or a fossil fuel source to install carbon monoxide alarms within the home.  Owners of multi-family leased or rental dwellings, such as apartment buildings, are required to comply with the law by January 1, 2013.

A carbon monoxide alarm is a stand alone unit which is tested to Underwriters Laboratory (UL) Standard 2034 and has its own built-in power supply and audible device.  These units are typically installed in single family dwellings.  A carbon

monoxide detector is a system unit which is tested to UL Standard 2075 and is designed to be used with a fire alarm system and receives its power from the fire alarm panel.

Existing CO devices installed prior to July 1, 2011 may continue to be utilized.

At this time the California Office of the State Fire Marshal is not aware of any requirement for a 10 year life battery for CO alarms.  However, if the device is a combination battery operated (primary power source) smoke/CO alarm, commencing

January 1, 2014, in order for the CA State Fire Marshal to approve and list the device, the device must display the date of manufacture, provide a place where the date of installation can be written, incorporate a hush feature, incorporate an end-of-life feature

providing notice that the device needs to be replaced, and, contain a non-replaceable, non-removable battery that is capable of powering the smoke alarm for a minimum of 10 years as required per Senate Bill 1394 recently chaptered into law.

Effective dates for installing a CO devices:

  • For a single-family dwelling having fossil fuel burning appliances and/or attached garages, the effective date is July 1, 2011.
  • For all other dwelling units having fossil fuel burning appliances and/or attached garages, the effective date is January 1, 2013.
  • For hotels and motels having fossil fuel burning appliances and/or attached garages, the effective date is January 1, 2016.


Additional Regulations for Rental Dwelling Units in San Francisco

Owners of a dwelling units intended for human occupancy in which one or more units is rented or leased are subject to additional requirements:

Reminder for Existing Smoke Alarms

When smoke alarms fail, it is usually because batteries are missing, disconnected or dead.  According to the National Fire Protection Association, the households with non-working smoke alarms now outnumber those with no smoke alarms.  Smoke alarms that are properly installed and MAINTAINED play a vital role in reducing fire deaths and injuries.  As most fatal fires occur at night, by taking the time to replace the batteries in your smoke alarms, you can sleep better knowing that you've provided one of the best ways to alert those in your household should a fire occur.

Smoke Alarm Tips:

  • Test smoke alarms once a month
  • Replace batteries in all 9 volt smoke alarms at least once a year (when you change your clocks)
  • Never remove the batteries from smoke alarms, not even temporarily
  • Regularly vacuum or dust smoke alarms to keep them working properly (at least once a year)
  • Replace smoke alarms every 10 years or per manufacturer's instructions
  • Don't paint over smoke alarms
  • Practice family fire drills so everyone knows what to do if the smoke alarm goes off


If you have any questions regarding the installation and maintenance of smoke alarms, or if you have any other questions about how to protect yourself and your household in the event of a fire, please contact the Bureau of Fire Prevention.